Surgical safety scalpel

ABSTRACT

A surgical safety scalpel comprising a blade, fixed at one end to an extended nose on a handle, covered with a sheath longitudinally slidably and inseparably mounted on said handle, said sheath comprising an elongated housing comprising an upper surface, a lower surface and two side surfaces connecting the upper and lower surfaces together, an aperture through said lower surface and a handle with a first button mounted on surface of said handle and aligned opposite to the said first button a second button wherein the said aperture on the sheath engages with the first button and second button in the blocking position of covering the said blade and wherein a base of the said sheath engages with a third button near the proximal end of tail of the said handle preventing the said sheath to slide of the handle when the sheath is in ready position and wherein the said second button also engages the said sheath from sliding over the said blade its exposed state and during use.

FIELD OF INVENTION

This invention relates generally to surgical scalpels and, moreparticularly, to surgical scalpels having shields or guards to cover thescalpel blade when not in use.

BACKGROUND OF THE INVENTION

In the world prevalent with AIDS epidemic and Hepatitis B and Cepidemics, accidental needle sticks and scalpel cuts have become a majorconcern to health-care worker. According to a study, the conversion ratefor HIV positive needle sticks is 1 in 250 sticks. The conversion ratefor scalpel cuts is unknown but according to a study of 10,000 healthcare workers, it is believed that the conversion rate is higher (as perU.S. Pat. No. 5,342,379). It is well known and understood by healthcareworkers that sharp surgical instruments, such as scalpels, have asignificant potential for harm to healthcare workers. The rapid handlingof these sharp instruments can lead to accidental cuts or puncturewounds during surgery.

Thus, there is an inherent incentive for improvement in the improvingscalpel technology that can reduce and more ideally eradicate scalpelcuts to the heal care worker. The chances of the healthcare workercontracting some fatal infection or disease because of accidentalscalpel cut comes with a heavily price on the society and theirhealthcare The scalpel has not had many basic changes made in the past100 years other than disposable blades and micro-surgical sizes.

Typically, maximum scalpel cuts or stabs occur in specific situations,such as a surgery. Another occasion is at the time of passing a usedscalpel to a scrub nurse. Another is when a surgeon swabs a bleeder andaccidentally stabs himself (when he forgets that the scalpel is in hisother hand). Trauma cases are another high risk situation in which anaccidental laceration can occur because there many people simultaneouslyworking on these cases and people are rushing to perform their tasks.Yet another case of accidental stabs is that the blade shield is lost ormisplaced, the scalpel becomes dangerous for practically anyone andeveryone in the proximity of the exposed scalpel blade. Another instanceis during the disposal of medical waste, stabbing may occur because ofaccidental removal of the blade shield.

During the course of a surgery, the healthcare worker will usuallyremove the shield and give the exposed scalpel blade to the doctor.Similarly after completion of the use of the scalpel, the surgeon mayhand the exposed scalpel blade to the healthcare worker for covering.This process results in loss of time and may cause accidental stabbingof the healthcare worker or the surgeon. During waste disposal, thedisposer is not usually careful in handling the waste and may handle thewaste roughly, which may result in removal of the shield (if already notattached) and cause stabbing. This could also lead to spread ofinfection in the general public. Thus, there is a need to protect thehealthcare workers from accidental scalpel stabs

To address this issue, the in the recent years, scalpels with disposableblade portions have been made. In this type of scalpel, the bladecomponent is detachable from the handle component and disposed of bydeposit in a special container. It will be appreciated, however, thatsuch disposable of blades still present a hazard to the individual whomust detach and transfer the blade component.

Similarly, blade shields have been developed to cover the scalpel bladewhen the scalpel is not in use. While early blade shields did helpreduce the potential for accidental cuts or puncture wounds, there weresome problem areas. For example, safety scalpels are known that have aretractable external sheath but they require two hands to operate. Someof the blade shields are awkward to operate. Others included complexmechanical mechanisms to move the shield, which mechanisms could beprone to mechanical failure.

Attempts have been made to cover the blade in the knives itself byproviding a hollow handle component with a slidable blade therein.Basically, these instruments employ the handle component as a sheath forthe blade component when not in use. Typically, such sheathable bladeassemblies are not contemplated for disposal after a single use.Furthermore, such cutting instruments do not provide a positive meansfor preventing the unsheathing of the blade portion by a carelesshandler when disposal of the blade is desired.

Therefore, it is an object of the invention to provide a surgicalscalpel assembly that reduces the complexity of prior known scalpeldevices and which also provides additional safety and manufacturingbenefits over known scalpel systems.

SUMMARY OF THE INVENTION

A surgical safety scalpel comprising a scalpel handle with a provisionto removably attach a disposal scalpel blade at one end and alongitudinally moveable blade sheath on the handle. The sheath issecurely attached to the scalpel handle and entirely covers the scalpelblade in closed and protective state or blocking position. The shieldcan be made to slide down towards the tail of the scalpel handle andlock on the central part of the scalpel handle when the scalpel blade isin its exposed state. The sheath is a hollow body that locks on thescalpel handle by windows provided on the lower part of the sheath whichwindows interlock with the stoppers/buttons at the proximal end of thescalpel blade attachment near the stem of scalpel blade. The firstbutton/stopper prevents the sheath to be dislodged when in blockingposition. During this blocking position the second stopper prevents thesheath from sliding down over the handle by radially exerting force onto a lowest part of the sheath. The second stopper is placed inside agroove/recess on the handle and projects outwards. The second button haselastic nature and exerts outwards force. When the sheath is in blockingposition the outward exerted force keeps the sheath in such blockingposition. When the sheath is ready position the tail stopper preventsthe sheath from sliding off the handle. The window may have a smallprojection inside the window extending parallel or substantiallyparallel to the handle, which projection interlocks with the firststopper in the blocking position. The sheath has a drip on the sheathsurface to assist in transition the sheath from ready position toblocking position over the blade and provide traction for the user.

The scalpel blade can be simply covered with the sheath by using onehand and more particularly one digit of the hand holding the scalpel toactuate release mechanism. The scalpel blade is covered by the shieldwith a shift of the thumb. This covering can be affected after each cuthas been made. The sheathing is a smooth single hand operation withoutany risk of cutting oneself.

An object and advantage of the invention is to provide a safety sheathfor the scalpel blade wherein the sheath forms an integral andinseparable part of the body of the scalpel.

Another object and advantage of this invention is that the sheath doesnot require to be removed from the scalpel blade during surgery.

Yet another object and advantage of this invention is the locking of thesheath on the body of the scalpel so that the sheath cannot be removedfrom the scalpel body easily or accidentally. Deliberate attempt and alot of force will be required to remove the shield from the body of thescalpel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the embodiment of the blade and sheath of theinstant invention together with a scalpel handle.

FIG. 2 is a perspective view of the blade and sheath of the presentinvention in the blocking position.

FIG. 3 is a cross-sectional view of the blade and sheath of the presentinvention in blocking position.

FIG. 4 is an exploded cross-sectional view of the interlocking mechanismwhen the sheath is in the blocking position.

FIG. 5 is a perspective view of the blade and sheath of the presentinvention together with a scalpel handle and arranged in the readycondition with the blade exposed.

FIG. 6 is a cross-sectional view of the blade and sheath of the presentinvention in ready position.

FIG. 7 is an exploded cross-sectional view of the interlocking mechanismwhen the sheath is in the ready position.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, there is shown a perspective view of one embodimentof the blade and sheath of the instant invention together with a scalpelhandle.

In particular, the scalpel handle 1 is of conventional shape andconfiguration. This handle is made of plastic, stainless steel or othersuitable material and of such nature that can withstand all types ofsterilization ranging from chemical to heat (both dry or wet) or anyother sterilisation. Typically, the distal end 14 on the tail 9 isrelatively thin while the gripping or middle portion 11 is somewhatthicker. The front end 12 of the scalpel handle generally takes theconfiguration of an extended nose 13 which is relatively narrow andincludes a groove and projection 13 on at least one edge thereof forreceiving a blade 2.

The scalpel handle 1 can taper in width towards the distal end 14 nearthe tail 9. On at least one of the surfaces of the handle 1, the scalpelhandle includes a plurality of ridges/stoppers/buttons 5, 6 and 9 andslots/recess/groove 7 and 13.

Typically, the distal end 14 of the handle 1 is somewhat rounded forconvenience. In addition, a shoulder 15 can be provided at the end ofthe scalpel adjacent to the inner end of the nose 13.

The sheath 3 is also disclosed. While not necessarily limited thereto,the sheath 3 is typically formed of a plastic material such as aconventional polymer material including but not limited to polystyrene,polycarbonate, polyurethane, polyethelene, phenol-formaldehyde resins,polybutylene and the like.

As shown in FIG. 1, a plurality of substantially parallel, transversestrips 11 are provided across the outer surface of the sheath 3. Thesestrips (or ridges) can be raised or depressed areas in the body of thesheath 3. The strips 11 provide additional traction or gripping surfacefor the user of the sheath 3.

An aperture or window 4 having a square shape is provided through theupper surface lower of the sheath 3. The aperture 4 is shaped to includea button/stopper 5 in order to correspond, cooperate and lock with thisfirst stopper 4 and second stopper 6 while enclosing the scalpel blade2. The second stopper 6 is provided just under the first stopper 4. Thesecond stopper 6 limits the movement of the sheath 3 relative to thescalpel handle 1 when in blocking position.

A representative blade 2 is shown. The shape of the cutting edge of theblade and so forth are representative only. It is well known that thereare many sizes, shapes and styles of scalpel blades. The inventiondescribed herein is intended to cooperate with virtually any bladeshape.

Typically, the blade 2 includes a slot 16 which is configured tocooperate with and engage the nose 13 of the handle 1. Typically, thenose is inserted into the larger portion of the slot 16 and slid forwardto engage the smaller end of the slot in the groove 17 in the nose 13.

In FIG. 2, scalpel blade 2 (not visible) is shown along with theposition thereof relative to the sheath 3. The blade 2 is stored withinthe sheath 3 for safe and secure handling thereof without a danger ofharm to the handler of the blade.

FIG. 3 illustrates the cross-sectional view of the sheath 3 in blockingposition and completely covering the blade 2. When the blade 2 (withinsheath 3) is to be attached to handle 1, the front end 12 of the handleis not covered by the sheath 3 and this sheath 3 is slid down on to themiddle portion 11 of the handle. The elongated nose 13 of the handle 1is inserted into and mates with the slot 16 in the blade in conventionalfashion. The scalpel is now in armed and ready position.

To disarm the scalpel without touching the exposed blade 2, the sheath 3that is resting on the middle portion 11 of the handle 1 is pushedsmoothly forward or upwards from the middle portion 11 over the blade 2till the sheath 3 completely covers the blade 3 and the forward motionof the sheath 3 is stopped by the engagement of the window 4 with firststopper 5 and second stopper 6 and the sheath 3 is then locked over theblade 2. The blocked scalpel can be now kept safely for future use bythe healthcare worker.

Referring now to FIG. 3, there is shown by cross section the conditionwherein the blade 2 is fully mounted onto the nose 12 of the handle 1.The sheath 3 covers the blade 2 and portion of the scalpel handle 1.When the cutting procedure is concluded, the sheath 3 is positioned overthe blade 2 by sliding the sheath 3 back over the blade 2 into theposition shown in FIG. 2.

When the sheath 3 is returned to the position shown in FIG. 2, the blade2 is covered and the scalpel device can be handled in any appropriatefashion without fear of an accidental cut therefrom.

Referring to FIG. 4 shows the exploded view of the locking mechanism ofthe sheath 3 with the scalpel handle 1. First stopper 5 engages with thelower portion 19 of the window 4 thereby stopping the sheath 3 fromslipping over the scalpel blade 2 after the sheath has completelyenclosed and secured the scalpel blade 2. So that the sheath does notslide down the handle 1 and continues to remain in blocking position,the second button/stopper 6 prevents the sheath 3 from sliding down byengaging with the base 18 of the sheath 3. Therefore, the window 4, thefirst stopper 5, second stopper 6 and the base 18 of the sheath 3 forman interlocking mechanism to retain the sheath 3 in the blockingposition.

The second button/stopper 6 is made of an elastic material. The secondstopper 3 can obviously be made of any material that has elasticproperties. This second stopper 6 acts as a spring. During readyposition of the sheath 3, the second stopper 6 has radial tensiontypical of a spring that exerts against the opposing inner walls 20 ofthe sheath. When the sheath 3 is activated and eventually comes to restin the blocking position, the second stopper 6 is freed from the innerwall 20 of the sheath 3 and the spring action or the radial tensioncauses the second stopper 3 to spring outwards. This outward springmovement of second stopper 6 results in providing a retaining means forthe sheath 3 to remain in the blocking position. The explodedcross-sectional view in FIG. 4 best explains the working of this secondstopper 6.

Referring now collectively to FIG. 5 and FIG. 6 there is shown a view ofthe sheath 3 and blade 2 mounted on the nose 12 of the handle 1. Thisview is to explain the construction and working of the scalpel whensheath 3 is in ready position.

In FIG. 5 with the sheath 3 retracted to expose the blade 2 for anysuitable cutting purposes or when it is desired to remove the blade 2from the handle 1, the sheath 3 is moved back over the blade and ontothe handle (as shown in FIG. 5). It is understood that the blade 2 issecurely fastened to the scalpel handle 1 as described above. The sheath2 has been withdrawn along the handle 1 by exerting pressure on the grip11. Typically, the grip 11 is operated by pulling downward thereon bythe user's thumb and index finger or any other finger and then by theinsertion of the handle 1 into the sheath 3.

It can be seen that the blade 2 is attached to the handle 1 but iscompletely exposed and ready for use or already used, as the situationmay be. The sheath 3 in the ready position and is resting on the middleportion 11 of the scalpel handle 1. The sheath 3 is comfortably mountedon the middle portion 11 of the handle 1 in such a position that thesheath 3 forms a part of the middle portion 11 of the handle 1. So thatthe sheath 3 does not slide off the handle 1, the handle is providedwith stopper 8 on the end proximal to the curved distal end of thehandle. This stopper 8 is in form of a projection from the surface ofthe handle 1. Indeed, this embodiment also envisages instead of aprojection, the stopper 8 can be in form of a recess or groove cut intothe surface of the handle 1 which interacts and mates with projectionsfrom inside the inner walls 20 of the sheath 3.

This position of the sheath 3 enables the scalpel with blade 2 can beused easily and effectively without any requirement to remove the sheath3 from the handle 1 and can indeed be slid into blocking position quiteeasily.

To unsheathe the blade 2, the sheath 3 can be pushed back and downwardsover the body of the handle 1. In this case, the force inserted on thesheath is sufficient to override the restraint caused by the button 6.In the preferred embodiment, the button 6 which is made of elasticmaterial and has radial tension directed inwardly relative to the sheath3 (see FIG. 7) and engages the sheath 3. This arrangement providesadditional security to prevent the sheath 3 from inadvertently slidingback over and covering the blade during a cutting procedure.

The length of the sheath 3 is such that it just covers the first button5 while resting on button 8. Furthermore, the length of the sheath 3 issuch that it completely covers the blade 2. Such a construction assistsin the preferred working of the sheath 3 but does not necessarily meanthat other combinations are not possible.

FIG. 7 shows the exploded cross-sectional view of the sheath 2 in readyposition. This figure shows the close up and clear picture of theworking of button 6 and the radial tension extending outwards into theinterior wall 20 of the sheath 3.

Thus, there is shown and described a unique design and concept of ascalpel blade cover. While this description is directed to a particularembodiment, it is understood that those skilled in the art may conceivemodifications and/or variations to the specific embodiments shown anddescribed herein. Any such modifications or variations which fall withinthe purview of this description are intended to be included therein aswell. It is understood that the description herein is intended to beillustrative only and is not intended to be limitative. Rather, thescope of the invention described herein is limited only by the claimsappended hereto.

1-10. (canceled)
 11. A surgical safety scalpel comprising a blade, fixedat one end to an extended nose on a handle, covered with a sheathlongitudinally, slidably and inseparably mounted on said handle, saidsheath comprising an elongated housing comprising an upper surface, alower surface and two side surfaces connecting the upper and lowersurfaces together, an aperture through said lower surface, and a handlewith a first button, mounted on the said handle, and a second buttonmounted on the handle, aligned opposite to said first button, whereinthe said aperture on the sheath engages with the first button and thesecond button when the sheath is in a blocking position, covering thesaid blade, and wherein a base of the said sheath engages with a thirdbutton near the proximal end of a tail of the said handle, preventingsaid sheath from sliding off of the handle when the sheath is in a readyposition, and wherein the said second button also engages with saidsheath to prevent it from sliding over the said blade during use. 12.The surgical safety scalpel as claimed in claim 11 comprising a handlewith first button mounted on the said handle for engaging aperture onthe sheath.
 13. The surgical safety scalpel as claimed in claim 11comprising a handle with a second button mounted just under the firstbutton to prevent the sheath from sliding down during the blockingposition or from sliding into blocking position when the blade is inuse.
 14. The surgical safety scalpel of claim 12 in which said firstbutton defines a slope going away from the blade and towards the tail ofthe handle, such a slope ending in a vertical drop on the surface of thehandle.
 15. The surgical safety scalpel as claimed in claim 11comprising a third button on the proximal end of the tail of the handle.16. The surgical safety scalpel of claim 15 in which said third buttonis in form a projection from the surface of the handle.
 17. The surgicalsafety scalpel of claim 15 in which the third button is in the form of arecess in the handle that mates with the projection inside the sheathwall.
 18. The surgical safety scalpel of claim 13 in which said secondbutton has a radial tension exerting outwards on the inner wall of thesheath wall in ready position.
 19. The surgical safety scalpel of claim13 in which said second button has a radial tension exerting outwards onto the base of the sheath during the blocking position.
 20. The surgicalsafety scalpel of claim 11 in which said sheath defines a grip on thesurface of the sheath to facilitate holding by the user.